Lifting-jack



(No Model.)

F. THOMAS.

v LIPTING JACK. No. 599,026. Patented Feb. 15, 1898.

&

lbw-ms. I Invent).

MAM :1 u/QM UNITED STATES PATENT OFFICE.

FREDERICK THOMAS, OF AURORA, ILLINOIS.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent N 0. 599,026, dated. February 15, 1898.

Application filed March 20, 1897. fierial'No. 628,526. (No model.)

To aZZ whom it may concern.-

Be it known that I, FREDERICK THOMAS, of Aurora, in the county of Kane and State of Illinois, have invented a new and Improved Lifting-Jack, of which the following is a specifioation.

In my drawings, Figure 1 represents a vertical central section of my improved liftingjack; and Fig. 2 is a plan view of same, showing the head of lifting-jack on the line Z Z with double-handle lever I connected to handle G of upward-toothed dog or stop C. Fig. 3 is a detail view of upward-toothed dog with handle G and round studs H H, over which spiral springs K K coil, are held in position, and operate on.

Letters of reference indicate corresponding parts.

My invention relates to an improved and safe lifting-j aok whereby the operator cannot meet with accident by the slipping or falling out of place ofthe liftingbar, my lifting-j ack to be made of malleable iron or other metal.

The invention consists of a hollow standard that guides a tubular or solid toothed liftingbar, into which the toothed and lever-acting block enters that raises the lifting-bar to support the same on a toothed dog or stop at any height. The actuating-lever is made in one piece, with round beaded stock or shank cast with taper hole to admit long taper-turned hard-wood lever when extra power is required for operating jack. on each side, over which side plates or links are placed. The upper end of links hang on pivots cast on head of standard and oscillate on them. The actuating-lever is fulcrumed to lower end of side links and oscillates in supporting standard or frame, made in one.

casting to guide the interior sliding liftingbar B. The lifting-bar can be made hollow or solid, as required. The lifting-bar B is The lever has trunnions square, recessed on either side of its toothed rack, and passes upward in standard A until its projecting foot or flange M stops at a. The standard A is cast with pivots on either side of head, on which hang the side plates or links E, one of which is shown, and which oscillate on these pivots. The actuating-lever F is hung in lower end of side plates and oscillates in them.

The raisin g-block D is fulcrumed in the actuating-lever F at N. The shaft N being to one side in the actuating-lever causes an upward forward and downward back motion of the lifting-block D when the actuating-lever F is oscillated. The oscillating or rocking links E admit the ready entrance of the block D into the teethof the lifting-bar B for'raising the same or the withdrawal of the same when it is desired to lower the lifting-bar.

'The lifting-block D has enough play in the surrounding casing of the standard that its teeth may clear the teeth of the bar B. For this purpose the casing of thestandard A is provided above the lifting-block D with an inclined plate I), up to which the block D may be raised, while its downward motion is defined by a recess and shoulder in the lower part of standard A. The toothed dog 0 is placed sidewise onthe inclined plate I) in the upper part of the standard and forced by combined spiral springs K K on guide-studs H H into the teeth of the lifting-bar B until released by being withdrawn on taking hold of either handle of the double-handle lever I, attached to handle Gof the same, that projects through a slot in the standard. The guidestuds H H, around which the spiral springs K K coil, pass through oblong holes in the standard A and serve to keep these springs in form and position. These springs being spiral rarely break and form a perfect cushion for the dog 0 to operate against.

The pushing up of the bar by the lifting block by means of the actuating-lever and oscillating plates or links and the instant support of the bar by the dog 0, operated by ICO encircling said studs, ahandle secured to said dog and extending through the standard, and a lever centrally pivoted to said handle and provided with cam-facesnear each end for I 5 engaging the standard, whereby the dog may be Withdrawn from engagement with the lifting-bar, substantially as described.

FREDERICK THOMAS. Witnesses:

WILLIAM F. FORBES, WILLIAM T. WINcHELL. 

